4-hydroxy-2-noneal (4-HNE) is produced in the mitochondria of those with excess amounts of linoleic acid (LA) in their diets. It turns out it's also important in Alzheimer's and other neuro-degenerative diseases.

"The mitochondrial enzyme ALDH2 exerts an important physiological protection in a variety of tissues, as it degrades highly toxic aldehydes originating from the lipid peroxidation cascade, mainly 4-HNE. Protection afforded by ALDH2 has been observed in conditions in which oxidative stress and the resulting excessive production of 4-HNE causes tissue damage, often evolving toward degenerative processes (Ohsawa et al., 2008; Wey et al., 2012). Thus, ALDH2 appears to be implicated in diverse pathologies such as Alzheimer’s and Parkinson’s diseases and ischemic conditions (Ohsawa et al., 2008; Wey et al., 2012). Here, we examined the role of ALDH2 in the development of endothelial dysfunction produced by the vasculotropic amyloid Ab (Ab1–40), known to be involved in the pathogenesis of the Alzheimer-associated cerebral amyloid angiopathy (CAA) (Donnini et al., 2010)."

So if they increase ALDH2, they decrease 4-HNE, and reduce the damage to the cell.

"The present work identifies a specific detoxifying mechanism, provided by activation of a mitochondrial enzyme, ALDH2, by means of the selective activator Alda-1. The protection of the vascular endothelium from injuries arising from toxic products of lipid peroxidation [4-HNE] afforded by this activator could have implications for a wide range of diseases in which impairment of mitochondrial function and angiogenesis are the underlying pathogenetic mechanism. Our findings, demonstrating that activation of ALDH2 by Alda-1, prevents the injurious effects of Ab on vascular endothelium and preserves angiogenic phenotype and responsiveness, may have applications for other age-related vasculopathies, including those associated with diabetes and vascular dementia."

"Alzheimer's disease (AD) exhibits extensive oxidative stress throughout the body, being detected peripherally as well as associated with the vulnerable regions of the brain affected in disease. Abundant evidence not only demonstrates the full spectrum of oxidative damage to neuronal macromolecules, but also reveals the occurrence of oxidative events early in the course of the disease and prior to the formation of the pathology, which support an important role of oxidative stress in AD. As a disease of abnormal aging, AD demonstrates oxidative damage at levels that significantly surpass that of elderly controls, which suggests the involvement of additional factor(s). Structurally and functionally damaged mitochondria, which are more proficient at producing reactive oxygen species but less so in ATP, are also an early and prominent feature of the disease. Since mitochondria are also vulnerable to oxidative stress, it is likely that a vicious downward spiral involving the interactions between mitochondrial dysfunction and oxidative stress contributes to the initiation and/or amplification of reactive oxygen species that is critical to the pathogenesis of AD.

There's another way to read that, of course, if one assumes that high levels of LA are not normal....

This next study is hilarious; yes, if you assume that high levels of LA (which don't exist naturally) are "normal" this would be a mystifying result:

"We report here the finding that normal,
young cartilages, in distinction from all other tissues exa- mined, have unusually high levels of n-9 eicosatrienoic
(20:3 cis-i5’8”) acid and low levels of n-6 polyunsaturated
fatty acids (n-6 PUFA)....

"...The finding of low levels of n-6 PUFA and high levels of unusual n-9 fatty acids, characteristic of EFA deficiency, in normal cartilage is remarkable in view of the fact that normal levels of EFA are present in serum, muscle, liver, kidney, and bone of the same animals (Tables 1-4). To properly understand this finding, it is important to recognize that when tissue from an EFA-deficient animal is transplanted into a nutritionally normal recipient, the EFA-deficient tissue rapidly recovers and regains a normal fatty acid profile within a period of 5 days (19). Thus it seemed implausible that a tissue should exhibit features characteristic of EFA deficiency in an animal with normal levels of EFA in its other tissues. Yet this phenomenon was consistently seen in normal cartilage of all species so far investigated (chicken, calf, human, rabbit, and pig)."

That's really the key question for metabolic syndrome, for as this paper observes:

"The centerpiece of the pathophysiologic mechanism of metabolic syndrome is insulin resistance. Recently, it is becoming evident that mitochondrial dysfunction is closely related to insulin resistance and metabolic syndrome...."

The "fatty acid hydroperoxides" (FA-OOH) they're discussing* are all from LA, as the paper makes not as clear as they should. Since they find that dysfunctional mitochondria have lots of LA hydroperoxides, they're looking to see if that's the cause or an effect.

"...Therefore, the purpose of this study was 1) to determine whether FA-OOH’s alter mitochondrial function (rate of ATP production, RCR [respiratory control ratio] and enzymatic activity of respiratory chain complexes) in skeletal muscle mitochondria and 2) to determine the effect of FA-OOH on the topology and sites of superoxide production, using methodologies that can distinguish between superoxide released towards the matrix and towards the intermembrane space...."

Well that sounds right. How'd they do?

"...We demonstrate for the first time that low micromolar concentrations of FA-OOH decreases the rate of mitochondrial ATP production, RCR and the enzymatic activity of respiratory chain complexes I and III in skeletal muscle mitochondria. Additionally, using methodologies that distinguish between superoxide generation towards the matrix and intermembrane space, we demonstrate that in skeletal muscle mitochondria, FA-OOH (but not FA-OH [fatty acid hydroxide**]) significantly increases the rate of mitochondrial ROS production directed towards the matrix (and not the intermembrane space) with complex I as the major site of ROS production."

So oxidized LA is bad for your mitochondria, increasing oxidation and decreasing energy production. The relevance of this finding is stated in the discussion:

"Previous studies by our group and others have shown that muscle atrophy is associated with an increase in mitochondrial oxidative stress and dysfunction [2, 7, 47, 48]. Our recent study showed that mitochondria isolated from atrophied muscles generate significant levels of lipid hydroperoxides [19]. However, no studies thus far have investigated the role of fatty acid hydroperoxides in the modulation of mitochondrial oxidative stress and dysfunction in skeletal muscle mitochondria."

They also note that this effect is not limited to just skeletal mitochondria:

"Other studies in heart, brain and liver mitochondria also indicate that fatty acids and fatty acid hydroperoxides are important modulators of mitochondrial respiration and ATP production [8, 11, 12, 49, 50]."

"Modulators" isn't the word I'd choose, but the point is the same.

Now based on the results described in yesterday's post, I wonder if the ROS they're finding directed into the matrix are coming from the cardiolipin itself, and not from complex I or III, as cardiolipin lines the matrix. But that's kind of an academic question.

*Why they're discussing "methyl linoleate" is a mystery to me, but whatever. Perhaps because that's what the suppliers are selling? Eating biodiesel seems like a bad idea that even a doctor could understand. As the results they're describing are consistent with other evidence, I'm not going to delve deeper into that mystery.

I noted that cardiolipin (CL) is the part of the mitochondria that is most subject to dysfunction, through oxidation of its linoleic acid (LA) constituents (it contains four, on an industrial diet, and is known as tetralinoyl CL (TLCL)). I found a study (2014) that looked at cardiolipin that didn't contain four LA:

"The structure of L3OCL has one of the LA side chains replaced by an oleic acid [OA]. According to our chemical mechanism of 4-HNE formation from CL, cross-chain peroxyl radical reaction occurs between two adjacent side chains; thus the presence of an unreactive oleic acid side chain in L3OCL may disrupt this reaction and lead to less lipid electrophile production through this mechanism."

And sure enough, they produced less oxidatively-damaged products:

"As shown in Fig. 4, our data showed that the formation of similar electrophiles EAA-CL from L3OCL was indeed significantly suppressed compared to those from L4CL, highlighting the importance of this cross-chain reaction during the formation of reactive electrophiles."

Then I found a study (PDF, 1985) that looked at mice that are deficient in LA. They replace the LA in their CL (which is only obtained through the diet) with OA (the main fat in olive oil. This is an omega-9 fat.):

"In the next study we find that, sure enough, if you feed mice an essential fatty acid (EFA) "deficient" diet (0.05% LA) their cardiolipin used OA (which the body can produce) in place of LA. They shifted from 58% LA to 70% OA.The diet they were fed was also deficient in DHA, apparently."

Nevertheless:

"Animals on the partially EFA-deficient diet (restriction of
linoleic acid to 10% of the control diet) were clinically normal,
although hair loss did occur in some animals after 6 months."

A bit of DHA in the diet likely would have cured the hair loss.
In making my argument, I noted that:

"Now the hole in this argument, at the moment, is that I can't find a study that looks at OXLAM production and cell apoptosis in a LA-restricted diet."

That's a bit of a mouthful, but what they did was pretty simple: they took OA (TPP- C18:1 in this study) and added it to CL, replacing the polyunsaturated fats (mostly LA) that are normally found there. OA acid is a monounsaturated fat, and is more resistant to oxidation—which is why olive oil is a good cooking fat. They did this in mouse embryonic cells (MEC), not in whole mice, as the next step was to give the cells a poison (actinomycin D, AcD) that causes CL oxidation and then apoptosis:

Then, just to make sure, they introduced a substance (triacsin C) that blocked integration of OA into the cells:

"We found that triacsin C treated cells exhibited high sensitivity to AcD-induced apoptosis and abolished the anti-apoptotic effect of TPP-C18:1 "

Not, apparently, being familiar with the 1985 study mentioned above, they noted that replacing LA with OA didn't seem to have any impact on the function of the mitochondria:

"It is possible that enrichment of mitochondria with oleoyl-containing CL molecular species may affect interactions of this essential anionic phospholipid with a number of mitochondrial proteins such as cyt c oxidase [47,48], creatine kinase [49,50], ATP synthase [51,52] mitochondrial ADP carrier [53] resulting in altered functional status. Our previous work, however, demonstrated that depletion of 55% of endogenous CL in HeLa cells did not affect their growth rate, mitochondria biomarker proteins and levels of ATP and mitochondrial membrane potential [28]. Further, cyt c binding constant for tetra-oleoyl-CL was similar to that of tetra-linoleoyl-CL [54]."

So everything looked good. Not suprising, given the 1985 results.However, that last sentence in that quote provides an additional, important clue. From Wikipedia:

"Cytochrome c is a highly conserved protein across the spectrum of species, found in plants, animals, and many unicellular organisms."

"Highly conserved" is a biological way of saying extremely important to the function of the electron transport chain (ETC), which means to life itself. This review of mitochondrial function—a neat read! (2009)—explains:

"Cardiolipin is a phospholipid found only in the IMM [inner-mitochondrial membrane] that anchors the mobile electron carrier cytochrome c to the IMM and optimizes the activity of electron-transport complexes, especially complex IV."

So a happy interaction between cyt c and cardiolipin is extremely important, and if it breaks down, as mentioned in the previous post, the mitochondria breaks, perhaps killing the cell it's in (apoptosis, again).

Now the usual explanation for LA-containing cardiolipin is that since it's right next to mitochondrial complex I, which is where most ROS are created, it's constantly getting oxidized. This is a pretty good model, but it turns out there's another mechanism for ROS generation in the mitochondria.

Although, according to Wikipedia, it's mostly an issue in chloroplasts, which are the mitochondria-analogue in plants.*

Anyway, it turns out that when cyt c touches (which it does constantly!) CL with four LA, it can cause ROS release.

"In the present study, we have investigated whether cyt c–CL
interaction could induce the generation of singlet oxygen.
Chemical trapping and luminescence measurements at 1270 nm
clearly showed the generation of singlet oxygen in cyt c incubation
with CL liposomes. Quantitative analysis revealed the
existence of at least two sources of singlet oxygen in our model,
one directly related to CL hydroperoxide decomposition and
another to CL oxidation."

And in their tests, this continued until there was no CL left!

"...Time dependent
formation of singlet oxygen generation was followed
by a parallel consumption of TLCL, reaching a saturation level
when CL was totally consumed (Fig. 1C and 5B). The decrease
in CL content was accompanied by the formation of CL monohydroperoxides
especially at the first few minutes of the incubation,
indicating that CL is being oxidized. This oxidation was
probably activated by small amounts of CL hydroperoxides
present in liposome preparations. It is important to note that
Kagan’s group reported an enhancement of up to 1000-fold in the peroxidase activity of cyt c–CL complexes in the presence of
fatty acid hydroperoxides, a process analogous to what happens
with COX-1 and 2.[40] Thus similarly to fatty acid hydroperoxides,
CL hydroperoxides can be used as a substrate necessary
to activate cyt c peroxidase activity."

It's a standard observation that older mitochondria have fewer, oxidized, or missing CL. Adding CL or LA to mitochondria made dysfunctional by CL oxidation actually improves function, as it's better than none. It seems that what they're describing here is a mitochondrial death spiral...

"Moreover, singlet oxygen formation was specifically observed for tetralinoleoyl CL species and
was not observed with monounsaturated and saturated CL species. Our results show that there are at least
two mechanisms leading to singlet oxygen formation: one with fast kinetics involving the generation of
singlet oxygen directly from CL hydroperoxide decomposition and the other involving CL oxidation.
The contribution of the first mechanism was clearly evidenced by the detection of labeled singlet
oxygen [18O2(
1
Δg)] from liposomes supplemented with 18-oxygen-labeled CL hydroperoxides. However
quantitative analysis showed that singlet oxygen yield from CL hydroperoxides was minor ( < 5%) and
that most of the singlet oxygen is formed from the second mechanism. Based on these data and previous
findings we propose a mechanism of singlet oxygen generation through reactions involving peroxyl
radicals (Russell mechanism) and excited triplet carbonyl intermediates (energy transfer mechanism).

"...This specificity is possibly related to the
ability of linoleoyl [LA] acyl chains to induce structural rearrangements
required for maximal activation of cyt c peroxidase
activity [43] and also to the higher oxidizability of this fatty acid
compared to oleoyl [OA] acyl chains."

"This process induces the formation of peroxyl radicals as well as excited triplet states, which are all known well established sources of singlet oxygen. The biological significance of singlet oxygen generated by the cyt c–CL complex needs to be further investigated. Nonetheless, our findings point to a potential role of singlet oxygen as an additional oxidant possibly involved in the pathway leading to cyt c release from mitochondria and induction of cell death."

P.S. It occurred to me that the demonstration of 4-HNE production (which is important for later posts) isn't demonstrated as strongly as I'd like.

So here (2011):

"...This novel mechanism for 4-HNE formation from CL oxidation in mitochondria may potentially have some physiological and pathophysiological significance. Generation of 4-HNE in vivo has been implicated in cardiovascular diseases, such as atherosclerosis [55], and neurodegenerative diseases including Alzheimer’s disease and Parkinson’s disease [5, 56–60]. L4CL [TLCL] is the major CL species in the mitochondria of most mammalian tissues and it constitutes more than 70% in the heart [61]. Thus formation of 4-HNE via this novel mechanisms is likely important. 4-HNE alters multiple essential functions of brain mitochondria, which plays a pivotal role in initiation and progression of neurodegenerative diseases [62]. 4-HNE also induces mitochondrial dysfunction and aberrant axonal outgrowth in adult sensory neurons that mimics features of diabetic neuropathy [63]....

"...In summary, we have provided evidence that 4-HNE and related reactive lipid electrophiles can be generated through a novel chemical mechanism of cardiolipin oxidation under free radical conditions in vitro and in vivo. This mechanism links 4-HNE generation to cardiolipin oxidation in mitochondria where abundant ROS are generated."

*LA is of course a PUFA that comes exclusively from plants, as animals don't produce it. I'll try not to read to much into that, but it turns out that LA in plants is subject to oxidative damage from singlet oxygen:

I thought I’d go over some of the stuff I’ve learned about this topic in the last five years I’ve been researching it.*

Your motor—one of them, anyway.

You the reader might want to stick with this post because, in my opinion and in that of a growing number of researchers, the “Diseases of Civilization”—aka the chronic diseases including the Metabolic Syndrome that now plague a large majority of Americans—may well all have one basic cause.
It turns out that there is a way of predicting who will gain or more easily lose weight. And it’s a pretty simple one, although not one that your local doctor will perform in the lab. It’s called the respiratory quotient—and don’t worry, this is it for the math!:

This tells the researchers, based on the proportion of (evil) carbon dioxide you exhale, what fuels your body is running on. If your RQ is 0.7, you’re burning nothing but fat for fuel, and if your RQ is 1.0, you’re burning nothing but carbohydrates for fuel.** Most of us are somewhat in the middle, naturally, but it turns out that if your RQ is at or near 1 all the time, it predicts two things: that you’re going to become obese, and that you’re going to have a hard time losing weight.
Which makes perfect sense, because an RQ of 1.0 all the time tells us that you’re unable to burn fat for fuel.

You’ve become a bathtub with a plug in the drain. You cannot lose fat mass because there’s nowhere for it to go.

What’s worse, if you reduce calorie intake, because your body is dependent on carbohydrates for fuel, your body is going to go to its major store of carbohydrates: your muscles. So you may wind up losing mostly muscle but little fat, if you’re in a really bad state.

Essentially this happens because your ability to burn fat atrophies from disuse. I came across one study a few years back that explained that in really hard-up obesity cases the fat stores inside the muscle cells actually move away from those motors in the picture above in your mitochondria, which are the engines of your body. Literally, they’re physically unable to burn fat.

And this is a bit of a problem.

As you can see from this graph, the available fuel stored in your body—and this is a lean person—is overwhelmingly in the form of fat. Assuming you’re lean, you have about 2,000 kilocalories of carbohydrate stored in your body, and about 40,000 kilocalories of fat.

So what do our Progressive overlords tell us our body runs on? Carbohydrates, of course! And they attempt to force our bodies to run on carbs through the dietary recommendations, which affects the foods available in our schools and markets.

They make a few recommendations, and they each have specific, predictable effects on our bodies.

Eat lots of carbs. The recommendations say 55-60%. This bolus of glucose (carbohydrates are for the most part just glucose, a simple sugar, in various forms) causes your body to release insulin, which tells your body to get rid of the glucose—which is toxic—any way possible. And insulin turns off fat-burning, because the body has a sudden requirement to dispose of glucose, and using fat for fuel gets in the way.This creates a cycle of glucose surge and glucose shortage, as your body’s ability to burn fat atrophies through disuse, which leads to that feeling known as “hangry” a few hours after a meal: the glucose has run out and your body goes into a panic. This is the typical post-lunch period of low energy.

Eat regular meals. They don’t mean three a day, they mean every couple hours. So when your body runs low on glucose you give it another dose. This keeps insulin elevated all the time, and since insulin turns off fat burning, guess what!

This advice to continuously eat a high-carb diet with a high percentage of omega-6 fats (see the first link at the top of this post) has been tested in rodents. It reliably makes them fat and diabetic—the Metabolic Syndrome. The simple measure of only allowing the rodents to eat during an eight-hour window prevents this, because they can use stored fats during the rest of the day, even if the same amount of calories is consumed.

This doctrine has even overtaken the athletic world, where we’re told that, since our bodies run on carbohydrates (see chart above again) you must consume carbs during sport. Perhaps you’ve heard of “the wall” that recreational marathoners hit at around 20 miles? This is “bonking”, where over-fat athletes run low on carbohydrates and sometimes collapse because they’re unable to switch smoothly to burn the massive amounts of fat they have stored. It even afflicts elite athletes.

And there’s another side to this story. It’s not just being overweight; scientists are beginning to recognize that many of our common chronic diseases feature malfunctioning mitochondria. This includes diabetes (of course), heart disease, and cancer, but also Alzheimer’s (often called type III diabetes) and other neurological diseases. Do you want to damage your mitochondria? Run them on glucose all the time.

So if, like me, you were a good Progressive drone and followed the advice of your betters, only to find yourself fat and paradoxically out of energy, what do you do?

Your fix your metabolism. You stop running your motor on glucose, which damages the motor, and you start running it on healthy, non-Omega-6 fats, which actually encourages your body to build more motors. You let it run the way it’s supposed to run.

Happily, this can be addressed by correcting two things: poor diet and lack of exercise. Yes, the doctors are right!—actually, not really.

We’ve already seen that their dietary recommendations cause the metabolic syndrome that afflicts the majority of Americans. Their exercise recommendations are similarly ill-considered. Rather than focus on strategies that help people to recover their lost ability to burn fat, they focus on high-intensity activities that simply promote using fuel from carbohydrates, as the body uses increasing amounts of carbohydrates the more intense the activity.

Fat-fueled.

So we want to do two things: run the motor on the right fuel, and push the motor to produce more energy while using the right fuel. Just as the ability to use fat for fuel atrophies with disuse, so can it be trained up to high levels of capacity, and in surprisingly short order.

"...It is tempting to classify endurance and ultraendurance sports as submaximal exercise, which might beneﬁt from increased fat utilization and a conservation of limited endogenous carbohydrate stores. However, the strategic activities that occur in such sports, the breakaway, the surge during an uphill stage, or the sprint to the ﬁnish line, are all dependent on the athlete’s ability to work at high intensities. With growing evidence that this critical ability is impaired by dietary fat adaptation strategies and a failure to ﬁnd clear evidence of beneﬁts to prolonged exercise involving self-pacing, it seems that we are near to closing the door on one application of this dietary protocol. Scientists may remain interested in the body’s response to different dietary stimuli and may hunt for the mechanisms that underpin the observed changes in metabolism and function. However, those at the coal-face of sports nutrition can delete fat loading and high-fat diets from their list of genuine ergogenic aids for conventional endurance and ultraendurance sports. [Emphasis mine]"

We've now seen a few athletes pursing high-fat diets win races, set course records, and even set a world record in the 12-hour track event.

And to her credit as a scientist, Burke published the paper in the title of this post in 2015. She revists the research that was available in 2006 when she published the "Nail in the Coffin" paper, and updates with research that has been done since then. (This was published prior to the FASTER study being released, so unfortunately does not include her thoughts on that, which is a shame.)

After noting that:

"...As a contributor to the evolution of the current sports nutrition guidelines, which have moved away from a universal approach to any aspect of the athlete’s diet, with particular effort to promote an individualized and periodized approach to both carbohydrate intake and carbohydrate availability during the training phase...

"...Indeed, modern sports nutrition practitioners teach athletes to manipulate their eating practices to avoid unnecessary and excessive intakes of carbohydrates per se, to optimize training outcomes via modification of the timing, amount and type of carbohydrate-rich foods and drinks to balance periods of low- and high-carbohydrate availability and to adopt well-practiced competition strategies that provide appropriate carbohydrate availability according to the needs and opportunities provided by the event and individual experience [14, 54–57]....

She goes on to conclude:

"The science and practice of these strategies is still evolving, and indeed, a final comment by this author on the current literature on LCHF diets for sports performance is that another reason for considering it incomplete is that the optimal ‘control’ (or additional intervention) diet has not yet been included in comparisons with fat-adaptation techniques. Future studies should investigate various LCHF strategies in comparison with the evolving model of the ‘carbohydrate-periodized’ training diet, rather than (or as well as) a diet chronically high in carbohydrate availability, to determine the best approaches for different individuals, different goals, and preparation for different sporting events. Considering that athletes might best benefit from a range of options in the dietary tool box is likely to be a better model for optimal sports nutrition than insisting on a single, one-size-fits-all solution."

So I guess the carbs-all-the-time "dogma" is dead. RIP.

"This article was published in a supplement supported by the Gatorade Sports Science Institute (GSSI)."

OK. This is, from what I know, a very fair assessment of where the science is on LCHF sports nutrition. She does not discuss race results, which is another shame, but at least she's open-minded.

From what I know, while there are a couple of athletes who say they pursue a ketogenic approach to training, and win races; the bulk of LCHF athletes do use carbs strategically, especially during races. It still remains to be seen if a keto diet is "better" in terms of pace during a race: I'm not aware of any evidence that it is.

But there are many ways to improve performance in a race. If you don't need to stop as much to eat, or can stop for shorter times, you're performing better. Even if your pace while moving is the same. If you can avoid the common dietary distress and related stops, you're going to perform better. And one common note is that recovery from events is much faster, which should improve performance over the course of a season, or on a multi-day event. Then we have the example of Kilian Jornet, who eats a high-carb diet, but trains fasted (8 hours at a go!), and appears to have a peerless fat-burning capability.

Science moves on, but it's nice to see it move in what I consider to be the right direction.

"'Dr. Niva Shapira of Tel Aviv University's School of Health Professions says that all eggs are not created equal. Her research indicates that when hens are fed with a diet low in omega-6 fatty acids from a young age — feed high in wheat, barley, and milo and lower in soy, maize and sunflower, safflower, and maize oils — they produce eggs that may cause less oxidative damage to human health. That's a major part of what determines the physiological impact of the end product on your table.'

"Eggs made from the conventional cheaper chicken diet produced worse effects on the blood of human study participants.

"'There were vast differences in outcome among the treatments. Daily consumption of two industry-standard eggs, high in omega-6, caused a 40 percent increase in LDL oxidizability in participants. After eating two per day of the specially-composed eggs, with both high anti-oxidant and low omega-6 levels, however, LDL oxidation levels were similar to the control group eating only two to four eggs a week....'"

That said, there's not much evidence that even industrially-produced eggs have a meaningful impact on cholesterol, but personally I choose the pay extra and eat pastured eggs. Plus, they taste better.

Sunday, February 21, 2016

"Nonalcoholic fatty liver disease (NAFLD) is a common and potentially serious form of chronic liver disease that occurs in patients who do not abuse alcohol. Present dietary recommendations for all Americans, including those with NAFLD, endorse a low-calorie, low-fat diet. However, little is known about the effect of diet composition on liver histopathology in patients with NAFLD. The aim of this study was to determine whether overall calorie intake and diet composition are associated with the severity of NAFLD histopathology....

...There were no significant associations between either total caloric intake or protein intake and either steatosis, fibrosis, or inflammation. However, higher CHO intake was associated with significantly higher odds of inflammation, while higher fat intake was associated with significantly lower odds of inflammation. In conclusion, present dietary recommendations may worsen NAFLD histopathology."

"Many successful ultra-endurance athletes have switched from a high-carbohydrate to a low-carbohydrate diet, but they have not previously been studied to determine the extent of metabolic adaptations....

"Compared to highly trained ultra-endurance athletes consuming an HC diet, long-term keto-adaptation results in extraordinarily high rates of fat oxidation, whereas muscle glycogen utilization and repletion patterns during and after a 3 hour run are similar."

The fat-burning rates and the lack of difference in glycogen consumption/replenishment are both game-changing findings. The glycogen findings are especially interesting, as they indicate that glycogen is being used for some purpose other than as fuel:

3.5. Muscle Glycogen
Compared to baseline, muscle glycogen was significantly decreased by 62% immediately post-exercise and 38% at 2 hours post-exercise in the HC group. The LC group exhibited a similar pattern; muscle glycogen was decreased by 66% immediately post-exercise and 34% at 2 hours post-exercise (Fig. 6A). There were no significant differences in pre-exercise or post-exercise glycogen concentrations between groups. There was a high degree of variability in muscle glycogen concentrations pre-exercise in both groups. In contrast, the depletion and resynthesis patterns showed a more uniform response, especially the amount of glycogen synthesized during the 2 hour recovery period in LC athletes (44.8 ± 7.5; 95% CI 40.2–49.4 μmol/g w.w.), which was one-third less variable than HC athletes (34.6 ± 23.9; 95% CI 19.8–49.4 μmol/g w.w.) (Fig. 6B). Interestingly, in all ten LC athletes the total amount of carbohydrate oxidized during the 3 hour run as calculated from indirect calorimetry (mean ± SD; 64 ± 25 g) was lower than the total amount of glycogen disappearance (mean ± SD; 168 ± 65 g), assuming 10 kg of active tissue.

So a low-carb diet means less variation in glycogen repletion, and no impact on glycogen levels or replenishment!

That sound you hear is the dietary recommendations for athletes being shattered...

Vespa, the company that apparently helped Phinney & Volek find the keto athletes involved, has a post here including the names of some of the athletes.

P.S. Not "apparently":

"The authors would like to thank Peter Defty for assistance in recruiting participants and the extraordinary research participants for their enthusiasm to participate in this project."

Given Barkha’s recent thread on obesity [members-only post behind paywall, but observes that many members of that site are overweight], I thought I’d sum up what I’ve learned about this topic in the past few years and some of what was discussed in that thread. I’m going to try to keep this concise and on-topic, so do not consider this to be a comprehensive analysis of the very large topic of human obesity. It is, I think, a reasonable theory that will explain the bulk (sorry) of the American obesity epidemic.

It’s Just Calories, Right?
What I’ll call the standard model of obesity is the notion that being overweight is the result of eating too much—and probably exercising too little—and that obesity is effectively the result of gluttony. The corollary to this is that you can eat whatever you want, so long as you eat “in moderation.”
While it’s true that in order to gain weight you must eat more calories than you expend, and that in order to lose weight you must expend more calories than you consume—this is known as physics—it turns out that this is not a particularly helpful observation when you consider living creatures like humans. Following that advice doesn’t work very well. In fact, for the majority of people who try it, it doesn’t work at all.

In terms of science, fat people are a very difficult group to study. As we saw in the comments to Barhka’s post, one quickly gets into multiple issues. Accusations of gluttony, sloth, lack of diligence (leading to lack of compliance with diet plans), and problems with the diet plans themselves make the whole topic a sea of confounding variables. It’s very difficult to boil things down to a reasonably likely sequence of cause and effect, and the calories-in-calories-out model boils down to blaming the obese for their affliction, which I don’t think is either correct or productive.

Fat Athletes
Let’s discuss Joe Friel. Joe eliminates many of the annoying variables that people run into when studying fat people:

He’s not a glutton: most of us would be happy to have his weight problem.

He’s not slothful: he’s been a competitive athlete for decades at this point, and exercises regularly to an extent most people could only hope to emulate.

He’s not lacking in diligence, as it takes a great deal of diligence to be a successful coach, author, and athlete over the course of decades. It doesn’t just happen, you have to work at it, and work hard.

And he’s certainly not lacking in knowledge about healthy diets, in fact, he wrote the book on it, originally published 10 years ago, and he has been following that diet for 21 years. (No, Mike H., this is not a post about that diet.)

In fact, Joe is a top athletic coach, with a long and successful career in triathlon. He was the coach of the American team, and wrote a book that’s considered the triathlete’s training bible. (If you’re not familiar with triathlon, it started with a race that consisted of a 2.4-mile swim, a 100-mile bicycle ride, and a marathon–26.2 miles). You can see why it’s known as the Ironman. While some folks do shorter versions, this is clearly not a group of people who are lacking for exercise.

Yet, nevertheless, he had a weight problem. He would follow the calories-in-calories out model, and lose weight during racing season. But he’d be miserable, always hungry. And then when he stopped exercising in the offseason—because you cannot keep up that level of activity year-round—he would gain weight.

He had a problem. Not any more.

“…The primary change I made was greatly reducing sugar and cutting back on fruit. I used to eat 5 to 7 servings of fruit a day. That’s roughly 600 calories of carbs from fruit, about 20 to 25% of my calories for the day….”

And as a result:

…The bottom line is that last fall I lost 8 pounds in 9 weeks by eating more fat and less carbohydrate. That was 5% of my body weight (160 pounds – at the time I was well on my way to my normal winter weight). I was never hungry. In fact, it seemed like the more fat I ate, the more weight I lost.

I learned that weight loss is not just calories in vs calories out. I used to lose weight that way. It works in the short term …

If a guy whose business it is to be fit can’t make the standard model of obesity work, who can? And Friel’s got company. The L.A. Lakers, Lindsey Vonn, Bode Miller, and Jenson Button are examples of top athletes who’ve lost weight using this approach while maintaining their competitive edge. Another top triathlon coach explains:

“Are we fated to be overfat? It’s a worldwide epidemic and it even affects many of those who workout regularly, including athletes….”

(We’re talking obesity, remember. We can get to health in another post, although there are no negative health implications I’m aware of.)

It’s Not Just Fat Humans…
Humans are the fattest primates. We’re supposed to have some fat on us, more than a racer like Joe Friel or a bodybuilder would like for their sports. (And women are supposed to have more fat than men—sorry, ladies.) Even for Joe Friel, it’s unlikely he would have become obese eating what he was eating, as people have been eating fruit since before we were human without getting obese.

Courtesy Dr. Stephan GuyenetSo with apologies to Gary Taubes and his books Good Calories, Bad Calories and Why We Get Fat, it seems that carbohydrates are a necessary but not sufficient idea to explain our obesity problem.
For that, we’re going to abandon athletes altogether and move on to rats. Obesity scientists love rats, mainly because they know exactly how to make rats obese. It’s as simple as ordering D12492 from Research Diets, and feeding it to rats. Voila!

“It tastes kind of like raw cookie dough, and the rats are crazy about it.”

But again, we have a confounder.

Because it’s not just rats in obesity labs fed D12492 that are getting fat. All the rats in the labs are getting fat. And the wild rats that live in our cities. (Rural rats also, but less so.) In fact, all the animals that live with and around humans, and depend on human foods are getting fatter. One scientists sums it up:

“Perhaps this problem isn’t as simple as just energy intake and energy expenditure, which has been the prevailing message over the last 10 years.”

“A recent international study fails to support the common belief that the number of calories burned in physical activity is a key factor in rising rates of obesity…. Diet is a more likely explanation than physical activity expenditure for why Chicago women weigh more than Nigerian women, Luke said….”

So much for that standard model of obesity.

So, to sum, if we’re looking for a dietary explanation for obesity, we’re looking for something that has the following attributes:

It’s new, not found in the wild.

It wasn’t a major part of the diet of the US in the 1920s.

Consumption has been increasing over the years as obesity’s been increasing.

It’s present in Research Diets’ D12492.

And, ideally, we have a mechanism to explain how this novel food causes obesity.

“It’s one of the most well-known effects of marijuana: the powerful surge in appetite many users feel after smoking or ingesting the drug, colloquially known as “the munchies.”…

And, as that article explains, we now know exactly how this happens:

“[Marijuana] appears to give us the munchies by convincing our brains that we’re starving.”

Chemically, by directly triggering appetite.

Now if the SoCons [Social Conservatives] would please resume their seats—no, it is not pot that is making us fat. Rats don’t smoke pot, for starters. But this system in our brains is named after marijuana, A.K.A. Cannabis.

(I’ve been trying to avoid geeking out, but bear with me for a moment.)

It turns out that the trigger in marijuana that activates the cannabinoid system, THC, mimics a chemical found in our brain, anandamide. Anandamide derives its name from the Hindu word ananda, which means “joy, bliss, delight“—perhaps you can see where this is going.

“Anandamide plays a role in the regulation of feeding behavior, and the neural generation of motivation and pleasure. In addition, anandamide injected directly into the forebrain reward-related brain structure nucleus accumbens enhances the pleasurable responses of rats to a rewarding sucrose taste, and enhances food intake as well.”

And sure enough:

“Independent studies in rodents and humans have shown a direct association between plasma [blood] anandamide levels and obesity.”

That’s “direct,” as in, if you inject a rat with THC or anandamide, they start eating [PDF], even if they’re full.

So all we need is some evidence that a food item that matches our 5-point list above increases anandamide levels, right?

To make it clear, the linoleic acid you eat is converted into anandamide in the body.

What Is Linoleic Acid?
LA, to its friends, is what’s known as an Omega-6 fat. It is primarily ingested in oils derived from seeds like soy, corn, or rapeseed (canola); but it bioaccumulates, like DDT, so you can ingest it via animals fed lots of seeds. That’s all industrially-raised pork, chicken, and turkey in the US.

Because this is far longer than I’d intended at this point, I’m going to wrap this up by going through my five-point test:

It’s new, not found in the wild.High levels of LA only entered the diet after the discovery of a means to detoxify cottonseed oil, which was an industrial waste at the time. This hit the big time with the introduction of Crisco in 1911. The low levels of LA found in a natural diet do not appear to be harmful.

It wasn’t a major part of the diet of the US in the 1920s.I’ll let Unilever, a major producer of foods based on seed oils explain:

“1920-1929: Unilever is formed. But during the decade the margarine market suffers declining demand as butter becomes more affordable.”

It really took off during the Depression, as it’s cheaper.

Consumption has been increasing over the years as obesity’s been increasing.Check.

“We are eating a lot more vegetable oil than we were in 1970. It comes chiefly from the industrial, omega-6 rich oils such as soybean, corn and canola.”

“It turns out that the diet obtains 32% of its fat from PUFA instead of the previously reported 17%. The ratio of omega-6 linoleic acid to omega-3 linolenic acid had been previously reported as 7.8 but is actually 14….”

The study I’ll link to again in point 5 seems to have been designed specifically to show that if you remove the LA from a diet like D12492, it no longer induces obesity.

So What Does This Mean For ME?
This is from an email I wrote in 2010 to the researcher who produced the chart above.

“ … Once of the first things I noticed after dropping [LA] from my diet was that I was no longer craving starch and sugar. I haven’t hit the candy bowl in 3+ weeks. Didn’t feel a need to .

“It makes me wonder if there might be a mechanism linking the two … ”

I’ve been avoiding carbs and LA ever since.

To eat LA “in moderation” in America means diligently avoiding many common foods, like salad dressing, as the “moderate” amount of LA is 2/3rds to 1/8th what most of us eat. But I’ve been weight-stable ever since, regardless of exercise level, and after years of regularly putting on weight each year. And I never worry about calories.

The scientists like to say, “more study is required.” And this is true in order to prove this link. But carbohydrates and seed oils are the primary ingredients in junk food. You don’t need a PhD to figure that one out.

The biggest problem in the Modern American Diet is that much of what we eat, much of what we’re told to eat, is what our parents and grandparents understood to be junk food.

Thursday, February 18, 2016

"Bronco Billy", as he calls himself, decided to go Paleo 7 weeks before a 100 mile ultra-marathon. I would have suggested to him that this was not a wise decision, as adaptation to a low-carb diet can take some time, and I wouldn't want to be responsible for a poor outcome. Here's what happened.

"The first week was horrible. I was lethargic, moody, and my workouts sucked. My kids were not hip to Dad’s new grouchy shortcomings. My body was deep in carb detox, starved of my normal intake of sugar, caffeine, and rice and potatoes. My body needed time to adapt to new fat-optimized pathways. I took my carb intake down to 15% of my daily intake, mostly from fresh veggies, about 20% protein from good natural meat sources, while upping my fat intake to 65%."

The reaction is not surprising, this is what's known as the "Atkins-" or "low-carb-flu". But, as a fit individual, he seemed to adapt pretty quickly:

"I started to come out of the carb-haze on day 8 and by 2 weeks in, I was feeling better. I cycled myself into ketosis.... I was starting to have consistent energy throughout the day. No lows, no crashes. I started to experiment with some carb-fasted runs with good success. I found I was able to run a 17-mile run after an 18-hour carb fast on only water and one s-cap [a salt tablet], with the last 12 at 50K race pace without any issues. I wasn’t even that hungry after the run. Not my normal.

"I started to go on my long 4-5 hour runs with only 50 calories per hour of Roctane drink with no bonks. I lost 7 pounds in the first 10 days and then stabilized at my high school weight of 135 pounds. My energy levels were solid. Recovery seemed to be faster too...."

So how'd the race go? Not stress-free, as he was pretty concerned about how this would work. Big changes before a race are a no-no, and every runner knows it's a recipe for disaster. But:

"I entered Paradise Aid Station at mile 27 in 4th place and left in the lead."

There are some open questions about whether a low-carb approach actually improves performance. It clearly doesn't impair it, but is it better? But there are many ways to improve performance. If your competitors have to stop frequently to carb-load, and you don't, you've just improved your performance, even if you're not actually going any faster. Anton Krupicka and Kilian Jornet both saw success with this approach (busted legs aside).

"As I came back to Paradise at mile 47 still in the lead, I was stoked. I felt good, I had no bonks, despite going on half the calories of my normal 100-mile nutrition plan. As I left, I yelled over my shoulder at my crew, Jesse Haynes, “It’s working! It’s working!” I was just as surprised. I had fretted quite a bit before the race, back up gels in all my drop bags, how much to take per hour? How would my body react? Sure it seemed to work in a 4-5 hour run, but what about at 12 hours? 16? My normal regimen was out the window, the regimen that had been working for years in 100s with good success."

Nevertheless, he won:

"I crossed the line in 21 hours, 22 minutes for my 14th 100-mile win and my 23rd hundred mile finish. So thankful and excited to grab another win and feel better than I have in a while, health-wise. Paleo and OFM are working well for me and I feel strong and excited for the 2016 season! Especially with both Western States 100 and Hardrock 100 on the schedule — a mere three weeks apart.

His review of the diet?

"The LCHF diet has been amazing. I just can’t say enough. I was able to go on half the calories I normally would intake in a 100-miler (GU Roctane, Vespa, unsweetened banana chips, and few orange wedges mainly). It’s a different, less traveled road, but worth it for the health benefits. My post-race recovery was like nothing I’ve experienced before. Truly unbelievable."

Better recovery is another way to improve performance even if you're not actually faster.

Congrats to Bronco Billy, on the win and on figuring out how to cure his health issues:

"I was a mess. I’d been fighting a candida/yeast issue in my GI tract since June and a staph infection I’d picked up in South America. I’d had to go on antibiotics for the staph, but this caused the yeast to get worse. I was dealing with my 4th major candida flare-up. When it would flare, I’d usually miss a night of sleep itching out of my mind, I was sick and tired of dealing with this issue.

"In a desperate state, I started researching anti-candida diets online and came across a Paleo forum talking about yeast and candida and that the Paleo lifestyle could help heal it. After all, yeast feeds on sugar and it made sense to cut out any yeast-feeding foods, especially starchy, sugary carbs. Plus, it helped that my wife had wanted to go Paleo for several years. She’d been dealing with some insulin resistance/hypoglycemia symptoms since her 20s. She already had two Paleo cook books. So, we embarked on cutting out grains, legumes, sugar, wine, beer and even coffee for good measure (I did bring back red wine in moderation after 4 weeks). It was 7 weeks from race day when I got full-on crazy strict — even through the holidays. I had no choice. I just couldn’t deal with another yeast flare-up."

See the comments on that post too, where some other top ultra-runners weigh in.

I find this somewhat surprising, as it does improve other aspects of the metabolic syndrome.

Metformin impairs the mitochondria's ability to use glucose as a fuel, which appears to have two effects: it reduces glucose use in the body, but it also reduces glucose production in the liver—which is the major cause of hyperglycemia (high blood sugar) in type II diabetes.

"...Sub-analysis of non-alcoholic fatty steatohepatitis showed that metformin failed to improve any pooled outcome. Adverse events were poorly reported. Current information indicates that metformin improves liver function, HOMA-IR and BMI to some extent, but not histological response in NAFLD patients...."

I suppose this is because the mitochodria still produces oxidative damage in the context of excess linoleic acid consumption, even if they're using fat instead of glucose as fuel. More study required!

Wednesday, February 17, 2016

The title of this study is a bit misleading. It's actually a fascination look into what a High-Fat, Low-Carb diet does in the body. This is an important paper because many scientists seem to think that because a high-fat diet makes peripheral tissues insulin resistant, and diabetes does the same, the two are therefore equivalent.

"...Six healthy men were studied on 3 occasions after consuming for 11 d diets with identical energy and protein contents but different percentages of energy as fat and carbohydrate as follows: 0% and 85% [low-fat, high-carbohydrate (LFHC) diet], 41% and 44% [intermediate-fat, intermediate-carbohydrate (IFIC) diet], and 83% and 2% [high-fat, low-carbohydrate (HFLC) diet]....

"Conclusion: A high-fat, low-carbohydrate intake reduces the ability of insulin to suppress endogenous glucose production and alters the relation between oxidative and nonoxidative glucose disposal in a way that favors storage of glucose."

But the meat isn't in the abstract. If we read on:

"...Remarkably, in the context of diabetes risk, 2 aspects of glucose homeostasis actually improved after consumption of the HFLC diet: decreased basal endogenous glucose production and improved insulin-stimulated nonoxidative glucose disposal. This observation might prove critical in the design of future studies."

Over-production of glucose by the liver is one of the signature features of type II diabetes, in fact, and is the main reason that those diabetics have hyperglycemia (high blood sugar).

This also helps to explain one of the more counter-intuitive findings of the FASTER study. This study explains:

"Even though the dietary fat content did not conclusively alter total glucose disposal, there were marked effects of dietary fat content on both oxidative and nonoxidative glucose disposal. Higher dietary fat contents resulted in increased insulin-stimulated nonoxidative glucose disposal and reduced carbohydrate oxidation, suggesting that insulin stimulates glycogen synthesis more effectively when dietary fat intakes increase and carbohydrate intakes decrease. This agrees with the increase in glycogen synthase activity by insulin observed after the consumption of high-fat diets (3). In contrast, the HFLC diet inhibited the stimulatory effects of insulin on glucose oxidation. Therefore, a high-fat, low-carbohydrate diet appears to result in a dissociation with respect to the effects of insulin on oxidative and nonoxidative glucose pathways."

The FASTER study (which I've not really blogged about, much to my surprise, just this) found that HFLC athletes used as much glycogen as high-carb athletes, and recovered glycogen stores just as quickly. If an HFLC diet promotes glycogen replenishment, that would explain how the glycogen stores recovered so quickly, as the liver's clearly capable of producing far more glucose than the body really needs, as demonstrated in type II diabetes.

I'll also note my post on thyroid hormones, which observes that much of the effect of glucose disposal is controlled by thyroid hormones, not just insulin. This study doesn't discuss that effect at all. The reduction in T3, which stimulates oxidative glucose disposal, could well explain this effect,

"“One of the runners we studied, a woman who has run multiple marathons and never been hurt, had some of the lowest rates of loading that we’ve ever seen,” said Irene Davis, a Harvard professor who led the study. She pounded far less than many runners who land near the front of their feet, Dr. Davis said. “When you watched her run, it was like seeing an insect running across water. It was beautiful.”"

“Think Easy, Light, Smooth, and Fast. You start with easy, because if that’s all you get, that’s not so bad. Then work on light. Make it effortless, like you don’t give a shit how high the hill is or how far you’ve got to go. When you’ve practiced that so long that you forget you’re practicing, you work on making it smooooooth. You won’t have to worry about the last one – you get those three, and you’ll be fast.”

It's the "practiced that so long that you forget you're practicing" part that trips most people up. If you rush it, in almost any sport, that's when you get hurt.

Friday, February 12, 2016

The funny thing about search engines is that once you find to the correct terms to look for, you start learning things very quickly.

"...In this study, we have demonstrated a “pathologic HDL phenotype” in subjects with PAH. This observation may reasonably be expected in our subjects with APAH as related to connective-tissue diseases; however, a similar magnitude of HDL dysfunction was noted in the IPAH cohort. This effect was further compounded by a significant increase in the normal proinflammatory influence of LDL in both PAH cohorts, as reflected by the increased LII [LDL Inflammatory Index] values. A 25–50-fold increase in plasma levels of oxidation products of both arachidonic acid [AA] (HETEs) and linoleic acid [LA] (HODEs) therein suggested a significant increase in “oxidant stress” contributing to the proinflammatory HDL dysfunction in PAH..."